[8833] | 1 | /* Parse C expressions for CCCP. |
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| 2 | Copyright (C) 1987, 1992, 1994, 1995 Free Software Foundation. |
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| 3 | |
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| 4 | This program is free software; you can redistribute it and/or modify it |
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| 5 | under the terms of the GNU General Public License as published by the |
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| 6 | Free Software Foundation; either version 2, or (at your option) any |
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| 7 | later version. |
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| 8 | |
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| 9 | This program is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 12 | GNU General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU General Public License |
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| 15 | along with this program; if not, write to the Free Software |
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| 16 | Foundation, 59 Temple Place - Suite 330, |
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| 17 | Boston, MA 02111-1307, USA. |
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| 18 | |
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| 19 | In other words, you are welcome to use, share and improve this program. |
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| 20 | You are forbidden to forbid anyone else to use, share and improve |
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| 21 | what you give them. Help stamp out software-hoarding! |
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| 22 | |
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| 23 | Written by Per Bothner 1994. */ |
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| 24 | |
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| 25 | /* Parse a C expression from text in a string */ |
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| 26 | |
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| 27 | #include "config.h" |
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| 28 | #include "cpplib.h" |
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| 29 | |
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| 30 | extern char *xmalloc PARAMS ((unsigned)); |
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| 31 | extern char *xrealloc PARAMS ((char *, unsigned)); |
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| 32 | |
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| 33 | #ifdef MULTIBYTE_CHARS |
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| 34 | #include <stdlib.h> |
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| 35 | #include <locale.h> |
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| 36 | #endif |
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| 37 | |
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| 38 | #include <stdio.h> |
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| 39 | |
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| 40 | /* This is used for communicating lists of keywords with cccp.c. */ |
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| 41 | struct arglist { |
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| 42 | struct arglist *next; |
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| 43 | U_CHAR *name; |
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| 44 | int length; |
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| 45 | int argno; |
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| 46 | }; |
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| 47 | |
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| 48 | /* Define a generic NULL if one hasn't already been defined. */ |
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| 49 | |
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| 50 | #ifndef NULL |
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| 51 | #define NULL 0 |
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| 52 | #endif |
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| 53 | |
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| 54 | #ifndef GENERIC_PTR |
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| 55 | #if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__) |
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| 56 | #define GENERIC_PTR void * |
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| 57 | #else |
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| 58 | #define GENERIC_PTR char * |
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| 59 | #endif |
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| 60 | #endif |
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| 61 | |
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| 62 | #ifndef NULL_PTR |
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| 63 | #define NULL_PTR ((GENERIC_PTR)0) |
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| 64 | #endif |
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| 65 | |
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| 66 | extern char *xmalloc (); |
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| 67 | |
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| 68 | #ifndef CHAR_TYPE_SIZE |
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| 69 | #define CHAR_TYPE_SIZE BITS_PER_UNIT |
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| 70 | #endif |
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| 71 | |
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| 72 | #ifndef INT_TYPE_SIZE |
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| 73 | #define INT_TYPE_SIZE BITS_PER_WORD |
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| 74 | #endif |
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| 75 | |
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| 76 | #ifndef LONG_TYPE_SIZE |
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| 77 | #define LONG_TYPE_SIZE BITS_PER_WORD |
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| 78 | #endif |
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| 79 | |
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| 80 | #ifndef WCHAR_TYPE_SIZE |
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| 81 | #define WCHAR_TYPE_SIZE INT_TYPE_SIZE |
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| 82 | #endif |
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| 83 | |
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| 84 | #ifndef MAX_CHAR_TYPE_SIZE |
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| 85 | #define MAX_CHAR_TYPE_SIZE CHAR_TYPE_SIZE |
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| 86 | #endif |
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| 87 | |
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| 88 | #ifndef MAX_INT_TYPE_SIZE |
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| 89 | #define MAX_INT_TYPE_SIZE INT_TYPE_SIZE |
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| 90 | #endif |
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| 91 | |
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| 92 | #ifndef MAX_LONG_TYPE_SIZE |
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| 93 | #define MAX_LONG_TYPE_SIZE LONG_TYPE_SIZE |
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| 94 | #endif |
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| 95 | |
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| 96 | #ifndef MAX_WCHAR_TYPE_SIZE |
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| 97 | #define MAX_WCHAR_TYPE_SIZE WCHAR_TYPE_SIZE |
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| 98 | #endif |
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| 99 | |
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| 100 | /* Yield nonzero if adding two numbers with A's and B's signs can yield a |
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| 101 | number with SUM's sign, where A, B, and SUM are all C integers. */ |
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| 102 | #define possible_sum_sign(a, b, sum) ((((a) ^ (b)) | ~ ((a) ^ (sum))) < 0) |
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| 103 | |
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| 104 | static void integer_overflow (); |
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| 105 | static long left_shift (); |
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| 106 | static long right_shift (); |
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| 107 | |
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| 108 | #define ERROR 299 |
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| 109 | #define OROR 300 |
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| 110 | #define ANDAND 301 |
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| 111 | #define EQUAL 302 |
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| 112 | #define NOTEQUAL 303 |
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| 113 | #define LEQ 304 |
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| 114 | #define GEQ 305 |
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| 115 | #define LSH 306 |
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| 116 | #define RSH 307 |
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| 117 | #define NAME 308 |
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| 118 | #define INT 309 |
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| 119 | #define CHAR 310 |
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| 120 | |
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| 121 | #define LEFT_OPERAND_REQUIRED 1 |
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| 122 | #define RIGHT_OPERAND_REQUIRED 2 |
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| 123 | #define HAVE_VALUE 4 |
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| 124 | /*#define UNSIGNEDP 8*/ |
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| 125 | |
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| 126 | #ifndef HOST_BITS_PER_WIDE_INT |
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| 127 | |
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| 128 | #if HOST_BITS_PER_LONG > HOST_BITS_PER_INT |
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| 129 | #define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_LONG |
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| 130 | #define HOST_WIDE_INT long |
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| 131 | #else |
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| 132 | #define HOST_BITS_PER_WIDE_INT HOST_BITS_PER_INT |
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| 133 | #define HOST_WIDE_INT int |
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| 134 | #endif |
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| 135 | |
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| 136 | #endif |
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| 137 | |
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| 138 | struct operation { |
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| 139 | short op; |
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| 140 | char rprio; /* Priority of op (relative to it right operand). */ |
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| 141 | char flags; |
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| 142 | char unsignedp; /* true if value should be treated as unsigned */ |
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| 143 | HOST_WIDE_INT value; /* The value logically "right" of op. */ |
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| 144 | }; |
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| 145 | |
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| 146 | /* Take care of parsing a number (anything that starts with a digit). |
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| 147 | LEN is the number of characters in it. */ |
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| 148 | |
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| 149 | /* maybe needs to actually deal with floating point numbers */ |
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| 150 | |
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| 151 | struct operation |
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| 152 | parse_number (pfile, start, olen) |
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| 153 | cpp_reader *pfile; |
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| 154 | char *start; |
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| 155 | int olen; |
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| 156 | { |
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| 157 | struct operation op; |
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| 158 | register char *p = start; |
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| 159 | register int c; |
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| 160 | register unsigned long n = 0, nd, ULONG_MAX_over_base; |
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| 161 | register int base = 10; |
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| 162 | register int len = olen; |
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| 163 | register int overflow = 0; |
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| 164 | register int digit, largest_digit = 0; |
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| 165 | int spec_long = 0; |
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| 166 | |
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| 167 | op.unsignedp = 0; |
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| 168 | |
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| 169 | for (c = 0; c < len; c++) |
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| 170 | if (p[c] == '.') { |
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| 171 | /* It's a float since it contains a point. */ |
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| 172 | cpp_error (pfile, |
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| 173 | "floating point numbers not allowed in #if expressions"); |
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| 174 | op.op = ERROR; |
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| 175 | return op; |
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| 176 | } |
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| 177 | |
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| 178 | if (len >= 3 && (!strncmp (p, "0x", 2) || !strncmp (p, "0X", 2))) { |
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| 179 | p += 2; |
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| 180 | base = 16; |
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| 181 | len -= 2; |
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| 182 | } |
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| 183 | else if (*p == '0') |
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| 184 | base = 8; |
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| 185 | |
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| 186 | /* Some buggy compilers (e.g. MPW C) seem to need both casts. */ |
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| 187 | ULONG_MAX_over_base = ((unsigned long) -1) / ((unsigned long) base); |
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| 188 | |
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| 189 | for (; len > 0; len--) { |
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| 190 | c = *p++; |
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| 191 | |
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| 192 | if (c >= '0' && c <= '9') |
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| 193 | digit = c - '0'; |
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| 194 | else if (base == 16 && c >= 'a' && c <= 'f') |
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| 195 | digit = c - 'a' + 10; |
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| 196 | else if (base == 16 && c >= 'A' && c <= 'F') |
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| 197 | digit = c - 'A' + 10; |
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| 198 | else { |
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| 199 | /* `l' means long, and `u' means unsigned. */ |
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| 200 | while (1) { |
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| 201 | if (c == 'l' || c == 'L') |
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| 202 | { |
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| 203 | if (spec_long) |
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| 204 | cpp_error (pfile, "two `l's in integer constant"); |
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| 205 | spec_long = 1; |
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| 206 | } |
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| 207 | else if (c == 'u' || c == 'U') |
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| 208 | { |
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| 209 | if (op.unsignedp) |
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| 210 | cpp_error (pfile, "two `u's in integer constant"); |
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| 211 | op.unsignedp = 1; |
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| 212 | } |
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| 213 | else |
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| 214 | break; |
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| 215 | |
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| 216 | if (--len == 0) |
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| 217 | break; |
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| 218 | c = *p++; |
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| 219 | } |
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| 220 | /* Don't look for any more digits after the suffixes. */ |
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| 221 | break; |
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| 222 | } |
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| 223 | if (largest_digit < digit) |
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| 224 | largest_digit = digit; |
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| 225 | nd = n * base + digit; |
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| 226 | overflow |= ULONG_MAX_over_base < n | nd < n; |
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| 227 | n = nd; |
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| 228 | } |
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| 229 | |
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| 230 | if (len != 0) |
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| 231 | { |
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| 232 | cpp_error (pfile, "Invalid number in #if expression"); |
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| 233 | op.op = ERROR; |
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| 234 | return op; |
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| 235 | } |
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| 236 | |
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| 237 | if (base <= largest_digit) |
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| 238 | cpp_warning (pfile, "integer constant contains digits beyond the radix"); |
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| 239 | |
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| 240 | if (overflow) |
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| 241 | cpp_warning (pfile, "integer constant out of range"); |
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| 242 | |
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| 243 | /* If too big to be signed, consider it unsigned. */ |
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| 244 | if ((long) n < 0 && ! op.unsignedp) |
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| 245 | { |
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| 246 | if (base == 10) |
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| 247 | cpp_warning (pfile, "integer constant is so large that it is unsigned"); |
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| 248 | op.unsignedp = 1; |
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| 249 | } |
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| 250 | |
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| 251 | op.value = n; |
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| 252 | op.op = INT; |
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| 253 | return op; |
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| 254 | } |
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| 255 | |
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| 256 | struct token { |
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| 257 | char *operator; |
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| 258 | int token; |
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| 259 | }; |
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| 260 | |
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| 261 | static struct token tokentab2[] = { |
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| 262 | {"&&", ANDAND}, |
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| 263 | {"||", OROR}, |
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| 264 | {"<<", LSH}, |
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| 265 | {">>", RSH}, |
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| 266 | {"==", EQUAL}, |
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| 267 | {"!=", NOTEQUAL}, |
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| 268 | {"<=", LEQ}, |
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| 269 | {">=", GEQ}, |
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| 270 | {"++", ERROR}, |
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| 271 | {"--", ERROR}, |
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| 272 | {NULL, ERROR} |
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| 273 | }; |
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| 274 | |
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| 275 | /* Read one token. */ |
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| 276 | |
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| 277 | struct operation |
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| 278 | cpp_lex (pfile) |
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| 279 | cpp_reader *pfile; |
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| 280 | { |
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| 281 | register int c; |
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| 282 | register int namelen; |
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| 283 | register struct token *toktab; |
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| 284 | enum cpp_token token; |
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| 285 | struct operation op; |
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| 286 | U_CHAR *tok_start, *tok_end; |
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| 287 | int old_written; |
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| 288 | |
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| 289 | retry: |
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| 290 | |
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| 291 | old_written = CPP_WRITTEN (pfile); |
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| 292 | cpp_skip_hspace (pfile); |
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| 293 | c = CPP_BUF_PEEK (CPP_BUFFER (pfile)); |
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| 294 | if (c == '#') |
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| 295 | return parse_number (pfile, |
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| 296 | cpp_read_check_assertion (pfile) ? "1" : "0", 1); |
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| 297 | |
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| 298 | if (c == '\n') |
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| 299 | { |
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| 300 | op.op = 0; |
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| 301 | return op; |
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| 302 | } |
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| 303 | |
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| 304 | token = cpp_get_token (pfile); |
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| 305 | tok_start = pfile->token_buffer + old_written; |
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| 306 | tok_end = CPP_PWRITTEN (pfile); |
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| 307 | pfile->limit = tok_start; |
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| 308 | switch (token) |
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| 309 | { |
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| 310 | case CPP_EOF: /* Should not happen ... */ |
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| 311 | op.op = 0; |
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| 312 | return op; |
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| 313 | case CPP_VSPACE: |
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| 314 | case CPP_POP: |
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| 315 | if (CPP_BUFFER (pfile)->fname != NULL) |
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| 316 | { |
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| 317 | op.op = 0; |
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| 318 | return op; |
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| 319 | } |
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| 320 | goto retry; |
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| 321 | case CPP_HSPACE: case CPP_COMMENT: |
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| 322 | goto retry; |
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| 323 | case CPP_NUMBER: |
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| 324 | return parse_number (pfile, tok_start, tok_end - tok_start); |
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| 325 | case CPP_STRING: |
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| 326 | cpp_error (pfile, "string constants not allowed in #if expressions"); |
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| 327 | op.op = ERROR; |
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| 328 | return op; |
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| 329 | case CPP_CHAR: |
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| 330 | /* This code for reading a character constant |
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| 331 | handles multicharacter constants and wide characters. |
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| 332 | It is mostly copied from c-lex.c. */ |
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| 333 | { |
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| 334 | register int result = 0; |
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| 335 | register num_chars = 0; |
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| 336 | unsigned width = MAX_CHAR_TYPE_SIZE; |
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| 337 | int wide_flag = 0; |
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| 338 | int max_chars; |
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| 339 | U_CHAR *ptr = tok_start; |
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| 340 | #ifdef MULTIBYTE_CHARS |
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| 341 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + MB_CUR_MAX]; |
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| 342 | #else |
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| 343 | char token_buffer[MAX_LONG_TYPE_SIZE/MAX_CHAR_TYPE_SIZE + 1]; |
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| 344 | #endif |
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| 345 | |
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| 346 | if (*ptr == 'L') |
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| 347 | { |
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| 348 | ptr++; |
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| 349 | wide_flag = 1; |
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| 350 | width = MAX_WCHAR_TYPE_SIZE; |
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| 351 | #ifdef MULTIBYTE_CHARS |
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| 352 | max_chars = MB_CUR_MAX; |
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| 353 | #else |
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| 354 | max_chars = 1; |
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| 355 | #endif |
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| 356 | } |
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| 357 | else |
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| 358 | max_chars = MAX_LONG_TYPE_SIZE / width; |
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| 359 | |
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| 360 | ++ptr; |
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| 361 | while (ptr < tok_end && ((c = *ptr++) != '\'')) |
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| 362 | { |
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| 363 | if (c == '\\') |
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| 364 | { |
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| 365 | c = cpp_parse_escape (pfile, &ptr); |
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| 366 | if (width < HOST_BITS_PER_INT |
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| 367 | && (unsigned) c >= (1 << width)) |
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| 368 | cpp_pedwarn (pfile, |
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| 369 | "escape sequence out of range for character"); |
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| 370 | } |
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| 371 | |
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| 372 | num_chars++; |
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| 373 | |
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| 374 | /* Merge character into result; ignore excess chars. */ |
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| 375 | if (num_chars < max_chars + 1) |
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| 376 | { |
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| 377 | if (width < HOST_BITS_PER_INT) |
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| 378 | result = (result << width) | (c & ((1 << width) - 1)); |
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| 379 | else |
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| 380 | result = c; |
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| 381 | token_buffer[num_chars - 1] = c; |
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| 382 | } |
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| 383 | } |
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| 384 | |
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| 385 | token_buffer[num_chars] = 0; |
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| 386 | |
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| 387 | if (c != '\'') |
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| 388 | cpp_error (pfile, "malformatted character constant"); |
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| 389 | else if (num_chars == 0) |
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| 390 | cpp_error (pfile, "empty character constant"); |
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| 391 | else if (num_chars > max_chars) |
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| 392 | { |
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| 393 | num_chars = max_chars; |
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| 394 | cpp_error (pfile, "character constant too long"); |
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| 395 | } |
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| 396 | else if (num_chars != 1 && ! CPP_TRADITIONAL (pfile)) |
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| 397 | cpp_warning (pfile, "multi-character character constant"); |
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| 398 | |
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| 399 | /* If char type is signed, sign-extend the constant. */ |
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| 400 | if (! wide_flag) |
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| 401 | { |
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| 402 | int num_bits = num_chars * width; |
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| 403 | |
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| 404 | if (cpp_lookup (pfile, "__CHAR_UNSIGNED__", |
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| 405 | sizeof ("__CHAR_UNSIGNED__")-1, -1) |
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| 406 | || ((result >> (num_bits - 1)) & 1) == 0) |
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| 407 | op.value |
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| 408 | = result & ((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); |
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| 409 | else |
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| 410 | op.value |
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| 411 | = result | ~((unsigned long) ~0 >> (HOST_BITS_PER_LONG - num_bits)); |
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| 412 | } |
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| 413 | else |
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| 414 | { |
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| 415 | #ifdef MULTIBYTE_CHARS |
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| 416 | /* Set the initial shift state and convert the next sequence. */ |
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| 417 | result = 0; |
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| 418 | /* In all locales L'\0' is zero and mbtowc will return zero, |
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| 419 | so don't use it. */ |
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| 420 | if (num_chars > 1 |
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| 421 | || (num_chars == 1 && token_buffer[0] != '\0')) |
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| 422 | { |
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| 423 | wchar_t wc; |
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| 424 | (void) mbtowc (NULL_PTR, NULL_PTR, 0); |
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| 425 | if (mbtowc (& wc, token_buffer, num_chars) == num_chars) |
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| 426 | result = wc; |
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| 427 | else |
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| 428 | cpp_warning (pfile,"Ignoring invalid multibyte character"); |
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| 429 | } |
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| 430 | #endif |
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| 431 | op.value = result; |
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| 432 | } |
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| 433 | } |
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| 434 | |
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| 435 | /* This is always a signed type. */ |
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| 436 | op.unsignedp = 0; |
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| 437 | op.op = CHAR; |
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| 438 | |
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| 439 | return op; |
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| 440 | |
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| 441 | case CPP_NAME: |
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| 442 | return parse_number (pfile, "0", 0); |
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| 443 | |
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| 444 | case CPP_OTHER: |
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| 445 | /* See if it is a special token of length 2. */ |
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| 446 | if (tok_start + 2 == tok_end) |
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| 447 | { |
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| 448 | for (toktab = tokentab2; toktab->operator != NULL; toktab++) |
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| 449 | if (tok_start[0] == toktab->operator[0] |
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| 450 | && tok_start[1] == toktab->operator[1]) |
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| 451 | break; |
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| 452 | if (toktab->token == ERROR) |
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| 453 | { |
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| 454 | char *buf = (char *) alloca (40); |
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| 455 | sprintf (buf, "`%s' not allowed in operand of `#if'", tok_start); |
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| 456 | cpp_error (pfile, buf); |
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| 457 | } |
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| 458 | op.op = toktab->token; |
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| 459 | return op; |
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| 460 | } |
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| 461 | /* fall through */ |
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| 462 | default: |
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| 463 | op.op = *tok_start; |
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| 464 | return op; |
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| 465 | } |
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| 466 | } |
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| 467 | |
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| 468 | |
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| 469 | /* Parse a C escape sequence. STRING_PTR points to a variable |
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| 470 | containing a pointer to the string to parse. That pointer |
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| 471 | is updated past the characters we use. The value of the |
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| 472 | escape sequence is returned. |
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| 473 | |
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| 474 | A negative value means the sequence \ newline was seen, |
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| 475 | which is supposed to be equivalent to nothing at all. |
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| 476 | |
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| 477 | If \ is followed by a null character, we return a negative |
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| 478 | value and leave the string pointer pointing at the null character. |
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| 479 | |
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| 480 | If \ is followed by 000, we return 0 and leave the string pointer |
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| 481 | after the zeros. A value of 0 does not mean end of string. */ |
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| 482 | |
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| 483 | int |
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| 484 | cpp_parse_escape (pfile, string_ptr) |
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| 485 | cpp_reader *pfile; |
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| 486 | char **string_ptr; |
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| 487 | { |
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| 488 | register int c = *(*string_ptr)++; |
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| 489 | switch (c) |
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| 490 | { |
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| 491 | case 'a': |
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| 492 | return TARGET_BELL; |
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| 493 | case 'b': |
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| 494 | return TARGET_BS; |
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| 495 | case 'e': |
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| 496 | case 'E': |
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| 497 | if (CPP_PEDANTIC (pfile)) |
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| 498 | cpp_pedwarn (pfile, "non-ANSI-standard escape sequence, `\\%c'", c); |
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| 499 | return 033; |
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| 500 | case 'f': |
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| 501 | return TARGET_FF; |
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| 502 | case 'n': |
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| 503 | return TARGET_NEWLINE; |
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| 504 | case 'r': |
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| 505 | return TARGET_CR; |
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| 506 | case 't': |
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| 507 | return TARGET_TAB; |
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| 508 | case 'v': |
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| 509 | return TARGET_VT; |
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| 510 | case '\n': |
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| 511 | return -2; |
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| 512 | case 0: |
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| 513 | (*string_ptr)--; |
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| 514 | return 0; |
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| 515 | |
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| 516 | case '0': |
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| 517 | case '1': |
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| 518 | case '2': |
---|
| 519 | case '3': |
---|
| 520 | case '4': |
---|
| 521 | case '5': |
---|
| 522 | case '6': |
---|
| 523 | case '7': |
---|
| 524 | { |
---|
| 525 | register int i = c - '0'; |
---|
| 526 | register int count = 0; |
---|
| 527 | while (++count < 3) |
---|
| 528 | { |
---|
| 529 | c = *(*string_ptr)++; |
---|
| 530 | if (c >= '0' && c <= '7') |
---|
| 531 | i = (i << 3) + c - '0'; |
---|
| 532 | else |
---|
| 533 | { |
---|
| 534 | (*string_ptr)--; |
---|
| 535 | break; |
---|
| 536 | } |
---|
| 537 | } |
---|
| 538 | if ((i & ~((1 << MAX_CHAR_TYPE_SIZE) - 1)) != 0) |
---|
| 539 | { |
---|
| 540 | i &= (1 << MAX_CHAR_TYPE_SIZE) - 1; |
---|
| 541 | cpp_warning (pfile, |
---|
| 542 | "octal character constant does not fit in a byte"); |
---|
| 543 | } |
---|
| 544 | return i; |
---|
| 545 | } |
---|
| 546 | case 'x': |
---|
| 547 | { |
---|
| 548 | register unsigned i = 0, overflow = 0, digits_found = 0, digit; |
---|
| 549 | for (;;) |
---|
| 550 | { |
---|
| 551 | c = *(*string_ptr)++; |
---|
| 552 | if (c >= '0' && c <= '9') |
---|
| 553 | digit = c - '0'; |
---|
| 554 | else if (c >= 'a' && c <= 'f') |
---|
| 555 | digit = c - 'a' + 10; |
---|
| 556 | else if (c >= 'A' && c <= 'F') |
---|
| 557 | digit = c - 'A' + 10; |
---|
| 558 | else |
---|
| 559 | { |
---|
| 560 | (*string_ptr)--; |
---|
| 561 | break; |
---|
| 562 | } |
---|
| 563 | overflow |= i ^ (i << 4 >> 4); |
---|
| 564 | i = (i << 4) + digit; |
---|
| 565 | digits_found = 1; |
---|
| 566 | } |
---|
| 567 | if (!digits_found) |
---|
| 568 | cpp_error (pfile, "\\x used with no following hex digits"); |
---|
| 569 | if (overflow | (i & ~((1 << BITS_PER_UNIT) - 1))) |
---|
| 570 | { |
---|
| 571 | i &= (1 << BITS_PER_UNIT) - 1; |
---|
| 572 | cpp_warning (pfile, |
---|
| 573 | "hex character constant does not fit in a byte"); |
---|
| 574 | } |
---|
| 575 | return i; |
---|
| 576 | } |
---|
| 577 | default: |
---|
| 578 | return c; |
---|
| 579 | } |
---|
| 580 | } |
---|
| 581 | |
---|
| 582 | static void |
---|
| 583 | integer_overflow (pfile) |
---|
| 584 | cpp_reader *pfile; |
---|
| 585 | { |
---|
| 586 | if (CPP_PEDANTIC (pfile)) |
---|
| 587 | cpp_pedwarn (pfile, "integer overflow in preprocessor expression"); |
---|
| 588 | } |
---|
| 589 | |
---|
| 590 | static long |
---|
| 591 | left_shift (pfile, a, unsignedp, b) |
---|
| 592 | cpp_reader *pfile; |
---|
| 593 | long a; |
---|
| 594 | int unsignedp; |
---|
| 595 | unsigned long b; |
---|
| 596 | { |
---|
| 597 | if (b >= HOST_BITS_PER_LONG) |
---|
| 598 | { |
---|
| 599 | if (! unsignedp && a != 0) |
---|
| 600 | integer_overflow (pfile); |
---|
| 601 | return 0; |
---|
| 602 | } |
---|
| 603 | else if (unsignedp) |
---|
| 604 | return (unsigned long) a << b; |
---|
| 605 | else |
---|
| 606 | { |
---|
| 607 | long l = a << b; |
---|
| 608 | if (l >> b != a) |
---|
| 609 | integer_overflow (pfile); |
---|
| 610 | return l; |
---|
| 611 | } |
---|
| 612 | } |
---|
| 613 | |
---|
| 614 | static long |
---|
| 615 | right_shift (pfile, a, unsignedp, b) |
---|
| 616 | cpp_reader *pfile; |
---|
| 617 | long a; |
---|
| 618 | int unsignedp; |
---|
| 619 | unsigned long b; |
---|
| 620 | { |
---|
| 621 | if (b >= HOST_BITS_PER_LONG) |
---|
| 622 | return unsignedp ? 0 : a >> (HOST_BITS_PER_LONG - 1); |
---|
| 623 | else if (unsignedp) |
---|
| 624 | return (unsigned long) a >> b; |
---|
| 625 | else |
---|
| 626 | return a >> b; |
---|
| 627 | } |
---|
| 628 | |
---|
| 629 | /* These priorities are all even, so we can handle associatively. */ |
---|
| 630 | #define PAREN_INNER_PRIO 0 |
---|
| 631 | #define COMMA_PRIO 4 |
---|
| 632 | #define COND_PRIO (COMMA_PRIO+2) |
---|
| 633 | #define OROR_PRIO (COND_PRIO+2) |
---|
| 634 | #define ANDAND_PRIO (OROR_PRIO+2) |
---|
| 635 | #define OR_PRIO (ANDAND_PRIO+2) |
---|
| 636 | #define XOR_PRIO (OR_PRIO+2) |
---|
| 637 | #define AND_PRIO (XOR_PRIO+2) |
---|
| 638 | #define EQUAL_PRIO (AND_PRIO+2) |
---|
| 639 | #define LESS_PRIO (EQUAL_PRIO+2) |
---|
| 640 | #define SHIFT_PRIO (LESS_PRIO+2) |
---|
| 641 | #define PLUS_PRIO (SHIFT_PRIO+2) |
---|
| 642 | #define MUL_PRIO (PLUS_PRIO+2) |
---|
| 643 | #define UNARY_PRIO (MUL_PRIO+2) |
---|
| 644 | #define PAREN_OUTER_PRIO (UNARY_PRIO+2) |
---|
| 645 | |
---|
| 646 | #define COMPARE(OP) \ |
---|
| 647 | top->unsignedp = 0;\ |
---|
| 648 | top->value = (unsigned1 || unsigned2) ? (unsigned long) v1 OP v2 : (v1 OP v2) |
---|
| 649 | |
---|
| 650 | /* Parse and evaluate a C expression, reading from PFILE. |
---|
| 651 | Returns the value of the expression. */ |
---|
| 652 | |
---|
| 653 | HOST_WIDE_INT |
---|
| 654 | cpp_parse_expr (pfile) |
---|
| 655 | cpp_reader *pfile; |
---|
| 656 | { |
---|
| 657 | /* The implementation is an operator precedence parser, |
---|
| 658 | i.e. a bottom-up parser, using a stack for not-yet-reduced tokens. |
---|
| 659 | |
---|
| 660 | The stack base is 'stack', and the current stack pointer is 'top'. |
---|
| 661 | There is a stack element for each operator (only), |
---|
| 662 | and the most recently pushed operator is 'top->op'. |
---|
| 663 | An operand (value) is stored in the 'value' field of the stack |
---|
| 664 | element of the operator that precedes it. |
---|
| 665 | In that case the 'flags' field has the HAVE_VALUE flag set. */ |
---|
| 666 | |
---|
| 667 | #define INIT_STACK_SIZE 20 |
---|
| 668 | struct operation init_stack[INIT_STACK_SIZE]; |
---|
| 669 | struct operation *stack = init_stack; |
---|
| 670 | struct operation *limit = stack + INIT_STACK_SIZE; |
---|
| 671 | register struct operation *top = stack; |
---|
| 672 | int lprio, rprio; |
---|
| 673 | |
---|
| 674 | top->rprio = 0; |
---|
| 675 | top->flags = 0; |
---|
| 676 | for (;;) |
---|
| 677 | { |
---|
| 678 | struct operation op; |
---|
| 679 | char flags = 0; |
---|
| 680 | |
---|
| 681 | /* Read a token */ |
---|
| 682 | op = cpp_lex (pfile); |
---|
| 683 | |
---|
| 684 | /* See if the token is an operand, in which case go to set_value. |
---|
| 685 | If the token is an operator, figure out its left and right |
---|
| 686 | priorities, and then goto maybe_reduce. */ |
---|
| 687 | |
---|
| 688 | switch (op.op) |
---|
| 689 | { |
---|
| 690 | case NAME: |
---|
| 691 | top->value = 0, top->unsignedp = 0; |
---|
| 692 | goto set_value; |
---|
| 693 | case INT: case CHAR: |
---|
| 694 | top->value = op.value; |
---|
| 695 | top->unsignedp = op.unsignedp; |
---|
| 696 | goto set_value; |
---|
| 697 | case 0: |
---|
| 698 | lprio = 0; goto maybe_reduce; |
---|
| 699 | case '+': case '-': |
---|
| 700 | /* Is this correct if unary ? FIXME */ |
---|
| 701 | flags = RIGHT_OPERAND_REQUIRED; |
---|
| 702 | lprio = PLUS_PRIO; rprio = lprio + 1; goto maybe_reduce; |
---|
| 703 | case '!': case '~': |
---|
| 704 | flags = RIGHT_OPERAND_REQUIRED; |
---|
| 705 | rprio = UNARY_PRIO; lprio = rprio + 1; goto maybe_reduce; |
---|
| 706 | case '*': case '/': case '%': |
---|
| 707 | lprio = MUL_PRIO; goto binop; |
---|
| 708 | case '<': case '>': case LEQ: case GEQ: |
---|
| 709 | lprio = LESS_PRIO; goto binop; |
---|
| 710 | case EQUAL: case NOTEQUAL: |
---|
| 711 | lprio = EQUAL_PRIO; goto binop; |
---|
| 712 | case LSH: case RSH: |
---|
| 713 | lprio = SHIFT_PRIO; goto binop; |
---|
| 714 | case '&': lprio = AND_PRIO; goto binop; |
---|
| 715 | case '^': lprio = XOR_PRIO; goto binop; |
---|
| 716 | case '|': lprio = OR_PRIO; goto binop; |
---|
| 717 | case ANDAND: lprio = ANDAND_PRIO; goto binop; |
---|
| 718 | case OROR: lprio = OROR_PRIO; goto binop; |
---|
| 719 | case ',': |
---|
| 720 | lprio = COMMA_PRIO; goto binop; |
---|
| 721 | case '(': |
---|
| 722 | lprio = PAREN_OUTER_PRIO; rprio = PAREN_INNER_PRIO; |
---|
| 723 | goto maybe_reduce; |
---|
| 724 | case ')': |
---|
| 725 | lprio = PAREN_INNER_PRIO; rprio = PAREN_OUTER_PRIO; |
---|
| 726 | goto maybe_reduce; |
---|
| 727 | case ':': |
---|
| 728 | lprio = COND_PRIO; rprio = COND_PRIO; |
---|
| 729 | goto maybe_reduce; |
---|
| 730 | case '?': |
---|
| 731 | lprio = COND_PRIO + 1; rprio = COND_PRIO; |
---|
| 732 | goto maybe_reduce; |
---|
| 733 | binop: |
---|
| 734 | flags = LEFT_OPERAND_REQUIRED|RIGHT_OPERAND_REQUIRED; |
---|
| 735 | rprio = lprio + 1; |
---|
| 736 | goto maybe_reduce; |
---|
| 737 | default: |
---|
| 738 | cpp_error (pfile, "invalid character in #if"); |
---|
| 739 | goto syntax_error; |
---|
| 740 | } |
---|
| 741 | |
---|
| 742 | set_value: |
---|
| 743 | /* Push a value onto the stack. */ |
---|
| 744 | if (top->flags & HAVE_VALUE) |
---|
| 745 | { |
---|
| 746 | cpp_error (pfile, "syntax error in #if"); |
---|
| 747 | goto syntax_error; |
---|
| 748 | } |
---|
| 749 | top->flags |= HAVE_VALUE; |
---|
| 750 | continue; |
---|
| 751 | |
---|
| 752 | maybe_reduce: |
---|
| 753 | /* Push an operator, and check if we can reduce now. */ |
---|
| 754 | while (top->rprio > lprio) |
---|
| 755 | { |
---|
| 756 | long v1 = top[-1].value, v2 = top[0].value; |
---|
| 757 | int unsigned1 = top[-1].unsignedp, unsigned2 = top[0].unsignedp; |
---|
| 758 | top--; |
---|
| 759 | if ((top[1].flags & LEFT_OPERAND_REQUIRED) |
---|
| 760 | && ! (top[0].flags & HAVE_VALUE)) |
---|
| 761 | { |
---|
| 762 | cpp_error (pfile, "syntax error - missing left operand"); |
---|
| 763 | goto syntax_error; |
---|
| 764 | } |
---|
| 765 | if ((top[1].flags & RIGHT_OPERAND_REQUIRED) |
---|
| 766 | && ! (top[1].flags & HAVE_VALUE)) |
---|
| 767 | { |
---|
| 768 | cpp_error (pfile, "syntax error - missing right operand"); |
---|
| 769 | goto syntax_error; |
---|
| 770 | } |
---|
| 771 | /* top[0].value = (top[1].op)(v1, v2);*/ |
---|
| 772 | switch (top[1].op) |
---|
| 773 | { |
---|
| 774 | case '+': |
---|
| 775 | if (!(top->flags & HAVE_VALUE)) |
---|
| 776 | { /* Unary '+' */ |
---|
| 777 | top->value = v2; |
---|
| 778 | top->unsignedp = unsigned2; |
---|
| 779 | top->flags |= HAVE_VALUE; |
---|
| 780 | } |
---|
| 781 | else |
---|
| 782 | { |
---|
| 783 | top->value = v1 + v2; |
---|
| 784 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 785 | if (! top->unsignedp |
---|
| 786 | && ! possible_sum_sign (v1, v2, top->value)) |
---|
| 787 | integer_overflow (pfile); |
---|
| 788 | } |
---|
| 789 | break; |
---|
| 790 | case '-': |
---|
| 791 | if (!(top->flags & HAVE_VALUE)) |
---|
| 792 | { /* Unary '-' */ |
---|
| 793 | top->value = - v2; |
---|
| 794 | if ((top->value & v2) < 0 && ! unsigned2) |
---|
| 795 | integer_overflow (pfile); |
---|
| 796 | top->unsignedp = unsigned2; |
---|
| 797 | top->flags |= HAVE_VALUE; |
---|
| 798 | } |
---|
| 799 | else |
---|
| 800 | { /* Binary '-' */ |
---|
| 801 | top->value = v1 - v2; |
---|
| 802 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 803 | if (! top->unsignedp |
---|
| 804 | && ! possible_sum_sign (top->value, v2, v1)) |
---|
| 805 | integer_overflow (pfile); |
---|
| 806 | } |
---|
| 807 | break; |
---|
| 808 | case '*': |
---|
| 809 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 810 | if (top->unsignedp) |
---|
| 811 | top->value = (unsigned long) v1 * v2; |
---|
| 812 | else |
---|
| 813 | { |
---|
| 814 | top->value = v1 * v2; |
---|
| 815 | if (v1 |
---|
| 816 | && (top->value / v1 != v2 |
---|
| 817 | || (top->value & v1 & v2) < 0)) |
---|
| 818 | integer_overflow (pfile); |
---|
| 819 | } |
---|
| 820 | break; |
---|
| 821 | case '/': |
---|
| 822 | if (v2 == 0) |
---|
| 823 | { |
---|
| 824 | cpp_error (pfile, "division by zero in #if"); |
---|
| 825 | v2 = 1; |
---|
| 826 | } |
---|
| 827 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 828 | if (top->unsignedp) |
---|
| 829 | top->value = (unsigned long) v1 / v2; |
---|
| 830 | else |
---|
| 831 | { |
---|
| 832 | top->value = v1 / v2; |
---|
| 833 | if ((top->value & v1 & v2) < 0) |
---|
| 834 | integer_overflow (pfile); |
---|
| 835 | } |
---|
| 836 | break; |
---|
| 837 | case '%': |
---|
| 838 | if (v2 == 0) |
---|
| 839 | { |
---|
| 840 | cpp_error (pfile, "division by zero in #if"); |
---|
| 841 | v2 = 1; |
---|
| 842 | } |
---|
| 843 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 844 | if (top->unsignedp) |
---|
| 845 | top->value = (unsigned long) v1 % v2; |
---|
| 846 | else |
---|
| 847 | top->value = v1 % v2; |
---|
| 848 | break; |
---|
| 849 | case '!': |
---|
| 850 | if (top->flags & HAVE_VALUE) |
---|
| 851 | { |
---|
| 852 | cpp_error (pfile, "syntax error"); |
---|
| 853 | goto syntax_error; |
---|
| 854 | } |
---|
| 855 | top->value = ! v2; |
---|
| 856 | top->unsignedp = 0; |
---|
| 857 | top->flags |= HAVE_VALUE; |
---|
| 858 | break; |
---|
| 859 | case '~': |
---|
| 860 | if (top->flags & HAVE_VALUE) |
---|
| 861 | { |
---|
| 862 | cpp_error (pfile, "syntax error"); |
---|
| 863 | goto syntax_error; |
---|
| 864 | } |
---|
| 865 | top->value = ~ v2; |
---|
| 866 | top->unsignedp = unsigned2; |
---|
| 867 | top->flags |= HAVE_VALUE; |
---|
| 868 | break; |
---|
| 869 | case '<': COMPARE(<); break; |
---|
| 870 | case '>': COMPARE(>); break; |
---|
| 871 | case LEQ: COMPARE(<=); break; |
---|
| 872 | case GEQ: COMPARE(>=); break; |
---|
| 873 | case EQUAL: |
---|
| 874 | top->value = (v1 == v2); |
---|
| 875 | top->unsignedp = 0; |
---|
| 876 | break; |
---|
| 877 | case NOTEQUAL: |
---|
| 878 | top->value = (v1 != v2); |
---|
| 879 | top->unsignedp = 0; |
---|
| 880 | break; |
---|
| 881 | case LSH: |
---|
| 882 | top->unsignedp = unsigned1; |
---|
| 883 | if (v2 < 0 && ! unsigned2) |
---|
| 884 | top->value = right_shift (pfile, v1, unsigned1, -v2); |
---|
| 885 | else |
---|
| 886 | top->value = left_shift (pfile, v1, unsigned1, v2); |
---|
| 887 | break; |
---|
| 888 | case RSH: |
---|
| 889 | top->unsignedp = unsigned1; |
---|
| 890 | if (v2 < 0 && ! unsigned2) |
---|
| 891 | top->value = left_shift (pfile, v1, unsigned1, -v2); |
---|
| 892 | else |
---|
| 893 | top->value = right_shift (pfile, v1, unsigned1, v2); |
---|
| 894 | break; |
---|
| 895 | #define LOGICAL(OP) \ |
---|
| 896 | top->value = v1 OP v2;\ |
---|
| 897 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 898 | case '&': LOGICAL(&); break; |
---|
| 899 | case '^': LOGICAL(^); break; |
---|
| 900 | case '|': LOGICAL(|); break; |
---|
| 901 | case ANDAND: |
---|
| 902 | top->value = v1 && v2; top->unsignedp = 0; break; |
---|
| 903 | case OROR: |
---|
| 904 | top->value = v1 || v2; top->unsignedp = 0; break; |
---|
| 905 | case ',': |
---|
| 906 | if (CPP_PEDANTIC (pfile)) |
---|
| 907 | cpp_pedwarn (pfile, "comma operator in operand of `#if'"); |
---|
| 908 | top->value = v2; |
---|
| 909 | top->unsignedp = unsigned2; |
---|
| 910 | break; |
---|
| 911 | case '(': case '?': |
---|
| 912 | cpp_error (pfile, "syntax error in #if"); |
---|
| 913 | goto syntax_error; |
---|
| 914 | case ':': |
---|
| 915 | if (top[0].op != '?') |
---|
| 916 | { |
---|
| 917 | cpp_error (pfile, |
---|
| 918 | "syntax error ':' without preceding '?'"); |
---|
| 919 | goto syntax_error; |
---|
| 920 | } |
---|
| 921 | else if (! (top[1].flags & HAVE_VALUE) |
---|
| 922 | || !(top[-1].flags & HAVE_VALUE) |
---|
| 923 | || !(top[0].flags & HAVE_VALUE)) |
---|
| 924 | { |
---|
| 925 | cpp_error (pfile, "bad syntax for ?: operator"); |
---|
| 926 | goto syntax_error; |
---|
| 927 | } |
---|
| 928 | else |
---|
| 929 | { |
---|
| 930 | top--; |
---|
| 931 | top->value = top->value ? v1 : v2; |
---|
| 932 | top->unsignedp = unsigned1 || unsigned2; |
---|
| 933 | } |
---|
| 934 | break; |
---|
| 935 | case ')': |
---|
| 936 | if ((top[1].flags & HAVE_VALUE) |
---|
| 937 | || ! (top[0].flags & HAVE_VALUE) |
---|
| 938 | || top[0].op != '(' |
---|
| 939 | || (top[-1].flags & HAVE_VALUE)) |
---|
| 940 | { |
---|
| 941 | cpp_error (pfile, "mismatched parentheses in #if"); |
---|
| 942 | goto syntax_error; |
---|
| 943 | } |
---|
| 944 | else |
---|
| 945 | { |
---|
| 946 | top--; |
---|
| 947 | top->value = v1; |
---|
| 948 | top->unsignedp = unsigned1; |
---|
| 949 | top->flags |= HAVE_VALUE; |
---|
| 950 | } |
---|
| 951 | break; |
---|
| 952 | default: |
---|
| 953 | fprintf (stderr, |
---|
| 954 | top[1].op >= ' ' && top[1].op <= '~' |
---|
| 955 | ? "unimplemented operator '%c'\n" |
---|
| 956 | : "unimplemented operator '\\%03o'\n", |
---|
| 957 | top[1].op); |
---|
| 958 | } |
---|
| 959 | } |
---|
| 960 | if (op.op == 0) |
---|
| 961 | { |
---|
| 962 | if (top != stack) |
---|
| 963 | cpp_error (pfile, "internal error in #if expression"); |
---|
| 964 | if (stack != init_stack) |
---|
| 965 | free (stack); |
---|
| 966 | return top->value; |
---|
| 967 | } |
---|
| 968 | top++; |
---|
| 969 | |
---|
| 970 | /* Check for and handle stack overflow. */ |
---|
| 971 | if (top == limit) |
---|
| 972 | { |
---|
| 973 | struct operation *new_stack; |
---|
| 974 | int old_size = (char*)limit - (char*)stack; |
---|
| 975 | int new_size = 2 * old_size; |
---|
| 976 | if (stack != init_stack) |
---|
| 977 | new_stack = (struct operation*) xrealloc (stack, new_size); |
---|
| 978 | else |
---|
| 979 | { |
---|
| 980 | new_stack = (struct operation*) xmalloc (new_size); |
---|
| 981 | bcopy ((char *) stack, (char *) new_stack, old_size); |
---|
| 982 | } |
---|
| 983 | stack = new_stack; |
---|
| 984 | top = (struct operation*)((char*) new_stack + old_size); |
---|
| 985 | limit = (struct operation*)((char*) new_stack + new_size); |
---|
| 986 | } |
---|
| 987 | |
---|
| 988 | top->flags = flags; |
---|
| 989 | top->rprio = rprio; |
---|
| 990 | top->op = op.op; |
---|
| 991 | } |
---|
| 992 | syntax_error: |
---|
| 993 | if (stack != init_stack) |
---|
| 994 | free (stack); |
---|
| 995 | skip_rest_of_line (pfile); |
---|
| 996 | return 0; |
---|
| 997 | } |
---|